The actress, 46, and the education activist, 45, have been together since 2004, according to the Free Press. Marinoni gave birth to their son, Max Ellington Nixon-Marinoni, in February 2011. Nixon has two children from her previous relationship with photographer Danny Mozes: Samantha, 12, and Charlie, 6.

PEOPLE also reported that the couple decided to wait to get married until it was legal to do so in New York State.

"I'm enjoying being engaged very much," Nixon told PEOPLE in 2010. "I don't mind a long engagement, which this one is surely turning out to be."